1. Field of the Invention
The present invention relates to a slider assembly for a read/write head in a rotating disc assembly and, more particularly, to a slider head assembly that has a thermally actuated distal end for controlling the height of the slider head with respect to the rotating disc.
2. Background Information
In disc drive applications, it is often desirable to provide a slider assembly with the capability to selectively adjust the position of a head with a read/write (RIW) element in relation to the disc itself. This capability is utilized to load and unload the head over the disc to disengage the head from a read/write position with respect to the disc while flying over the disc, and to dynamically adjust the fly height of the head while reading and/or writing the data to and from the disc.
One solution for on-demand engagement and disengagement of the head involves machining a slot in the proximal end of the slider carrying the head assembly and fastening a piezoelectric stack in the slot, such as by an adhesive. Activating the piezoelectric stack causes the slider to bend, thereby moving the head assembly carried in the slider in proximity with the disc for the read/write operation. However, this solution is not suitable for mass production, making it prohibitively expensive and time consuming for manufacturing in any substantial quantity. Other solutions also have significant drawbacks such as an inability to scale with decreased slider dimensions.
Thus, there is a need for a head assembly to provide selective engagement and disengagement of a read/write head in proximity with a disc but can be easily actuated to control the height of the head assembly over the disc.
According to the present invention, a slider head assembly is provided which includes a slider head for reading/writing data on the surface of a rotating disc. The slider head is disposed in spaced relationship with respect to the disc for read/write (R/W) operations. The slider head assembly is comprised of a body portion having an essentially planar surface positioned to co-act with the surface of the disc with a proximal end and a distal end. The proximal end or trailing slider surface of the head assembly has a read/write element thereat. The distal end or leading slider surface of the assembly has an actuation device mounted thereon, having a surface the position of which can be modified by an external signal to change the position of the head with respect to the planar or air bearing surface (ABS) of the head assembly. This will change the characteristics of the boundary layer of air between the rotating disc and the head, causing the head assembly to move closer to or farther from the rotating disc when actuated by the external signal. A preferred embodiment is a patterned heating element which selectively heats the edge of the leading surface of the slider to cause position modification of the device. The invention also contemplates the head assembly in combination with the rotating disc and a method of controlling the height of the head assembly with respect to the rotating disc.